In relation to recent portable cellular phones having phone functions, a two-housing-type portable cellular phone has become predominant. In some of the two-housing-type portable communications terminals, two housings are collapsible (a state where two housings of the portable communications terminal overlap each other is hereinafter called a “closed state,” and another state where the two housings do not overlap each other is hereinafter called an “open state.”) In the case of the closed state, pieces of various types of information are displayed by a sub-display portion located in an exterior side of the housing. In the case of the open state, pieces of various types of information are displayed in a main display portion located at an area where the two housings overlap each other in the closed state (a display area of the main display portion is usually larger than that of the sub-display portion, and hence, in many cases, simplified information having a small amount of information is displayed in the sub-display portion and detail information—which has a large amount of information and is easy to browse—is displayed in the main display portion).
In Patent Document 1, there is proposed a collapsible communications terminal device which displays occurrence of nonresponse to a voice call, information about a newly-arrived mail, and the presence or absence of a memorandum message, or the like, by utilization of the portable communications terminal. The collapsible communications terminal of Patent Document 1 displays, in a closed state, simplified information about the history of incoming calls (incoming calls, received mails, or the like) in the sub-display portion. Upon detection of the portable communications terminal having been opened by the user who has ascertained simplified information about the history of incoming calls, the portable cellular phone displays in the main display portion detailed information about the history of incoming calls (in the case of incoming calls, a time of receipt of a call, source information, a list of incoming calls; and in the case of an E-mail, a time of receipt of a mail, source information, a title, and the like).
According to the collapsible communications terminal of Patent Document 1, when the user ascertains detail information about the history of incoming calls by opening the terminal, there is no necessity for performing switching operation for displaying an incoming call history screen. Hence, efforts on the part of the terminal user can be lessened.
Patent Document 1: Japanese Patent No. 3530475